The 5 Key Differences are this:

1. Dragons are a Nickname for Drakonians, Not a species

2. Drakonians are more for a Sci Fi Settings, where Dragons are more Fantasy to a Mix

3. Drakonians are always a form of Western Dragon and have Clear to Heavy Scale marks on there body mostly in the Arms to Legs up to the Joints to some parts of the face and chest with Glowing Eyes and Chest

4. Drakonians DONT have Elemental Power and best can do is a "Breath" Attack from time to time but its mostly for tricks and last resort
However this did lead them to creating New Particle Tech or Elemental Tech that could make it look there using Elements

5. Drakonians have Rival and Hate to the Huntoai Species, where Dragons dont have Rival but do Hate Demons and Humans for number of reasons

Link to Drakonians: https://www.furaffinity.net/view/49338642/